Whereas Win7 will run on a 1ghz cpu with 512mb of ram, I would highly advise at minimum a dual core 1.5ghz-2ghz processor with at minimum 2gb of ram...

A real world spec though would end up 2.5ghz or so dual/quad core with 2-4gb ram and 250gb+ hard drive space... And it's even affordable now (we're talking a 4gb ram 3ghz quad core with a 2tb raid array disk for under a grand).
Donate to UGN Security here.
UGN Security, Back of the Web, Elite Web Gamers & VNC Web Design Owner